Registro DMARC
v=DMARC1; p=reject; rua=mailto:dmarc_rua@emaildefense.proofpoint.com; ruf=mailto:dmarc_ruf@emaildefense.proofpoint.com;fo=1

Servidores DNS Principal (mname) y Secundario (rname)
host: 1800shelter.org
class: IN
ttl: 900
type: SOA
mname: ns-1470.awsdns-55.org
rname: awsdns-hostmaster.amazon.com
serial: 1
refresh: 7200
retry: 900
expire: 1209600
minimum-ttl: 86400